The disclosure proceeds from a generic apparatus or method according to the independent claims. The subject matter of the present disclosure also relates to a computer program.
As a rule, light guides such as optical fibers or optical waveguides, for example, consist of a core and a cladding, with the light-guiding effect based on total-internal reflection arising on account of the core having a higher refractive index in comparison with the cladding.
Particularly in the field of telecommunications, the differences between the refractive indices may be very small, for instance less than 0.05.
Light guides for sensor applications, such as, for instance, in the field of absorption spectroscopy, may be embodied, for example, to split, for reference measurements, a light beam emanating from a light source and, in the process, guide as much light as possible to a sensitive unit. The light beam can be split with the aid of, for instance, plane light guide structures such as Y-couplers.